The resistance of Piper aduncum, P. arboreum, P. carniconnectivum, P. colubrinum, P. hispidinervium, P. hispidum, P. hostmannianum, P. nigrum, P. tuberculatum and Piper sp. to the infection caused by two Nectria haematococca f. sp. piperis isolates was detected under laboratory and shade house conditions. Due to their high susceptibility, black pepper (Piper nigrum) plants were used as control. When grown in soil infested with the isolate from P. aduncum (Adu), no root rot symptoms were observed on the majority of Piper spp., except on Piper sp. and black pepper. However, in soil infested with the isolate from P. nigrum (Nig) root rot was noticed on black pepper, although not on the other Piper spp. Significant differences (p<0.01) were observed when stems of Piper spp. plants were inoculated with Adu and Nig isolates. On P. nigrum stems typical lesions were followed by yellowish, stem blight and death of plants were observed, while on Piper spp. canker-like tissues around stem lesions were detected, evidencing the high resistance of these related species. These results showed that the isolate from P. aduncum has no ability to colonise Piper spp. root tissues and that at least seven related species are highly resistant to N. haematococca f. sp. piperis. This suggests that these species may be used either as rootstocks or for somatic hybridisation and protoplast fusion in amelioration studies aiming to control Fusarium diseases on black pepper.
Key-wordsresistance source; root rot; disease control; Fusarium solani f. sp. piperis; black pepper